反应详情

4-Hydroxy-2-(trifluoromethyl)benzoic acid (30.0 g) was dissolved in methanol (600 ml), thereto was added dropwise conc. sulfuric acid (10 ml). Then, the mixture was refluxed with stirring for 20 hours. The mixture was cooled to room temperature, and to the reaction mixture was added water (200 ml), and methanol was removed by evaporation, and the resultant was extracted twice with ethyl acetate (300 ml). The organic layer was washed with water, a saturated aqueous sodium hydrogen carbonate solution and a saturated aqueous sodium chloride solution, dried over sodium sulfate, filtered and concentrated under reduced pressure to give the title compound (32.0 g).

1. temperatureThen, the mixture was refluxed
2. customwas removed by evaporation
3. extractionthe resultant was extracted twice with ethyl acetate (300 ml)
4. washThe organic layer was washed with water
5. dry with materiala saturated aqueous sodium hydrogen carbonate solution and a saturated aqueous sodium chloride solution, dried over sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure